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RAC Node Does Not See Presented Disks (Doc ID 2411648.1)

Last updated on JUNE 11, 2020

Applies to:

Oracle VM - Version 3.4.1 and later
Oracle Cloud Infrastructure - Version N/A and later
Information in this document applies to any platform.


A disk was added to a VM using Oracle VM Manager, but the VM don't see that disk.

Dom0 show the new disk (/dev/mapper/360002ac0000000000000020f000055c0,xvdak), but the VM does not see them.

Running dmesg on the VM:

The system process "xenwatch" fail to allocate 6 continuous memory pages, and that's why it fail to attach the disks.
[578572.007045] xenwatch: page allocation failure: order:5, mode:0xc0d0
[578572.007055] CPU: 0 PID: 38 Comm: xenwatch Tainted: P OE 4.1.12-37.6.3.el6uek.x86_64 #2
[578572.007059] Hardware name: Xen HVM domU, BIOS 4.4.4OVM 09/06/2016
[578572.007063] 0000000000000005 ffff88062a14b7d8 ffffffff816bc5bc ffff88062a148000
[578572.007070] 000000000000c0d0 ffff88062a14b868 ffffffff81189e3a 0000000000000040
[578572.007076] ffff88062a01d400 ffff88062a14b818 ffffffff816bcf49 ffff88062a14b9a8
[578572.007081] Call Trace:
[578572.007094] [] dump_stack+0x48/0x5c
[578572.007102] [] warn_alloc_failed+0xea/0x140
[578572.007108] [] ? preempt_schedule_common+0x29/0x50
[578572.007112] [] ? _cond_resched+0x1d/0x30
[578572.007118] [] __alloc_pages_slowpath+0x3f9/0x750
[578572.007125] [] __alloc_pages_nodemask+0x28e/0x2b0
[578572.007133] [] alloc_pages_current+0xaf/0x170


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